CMAA Construction Management Practice Exam

The longest sequence of activities that determines the minimum project duration is the critical path. It is the path through the project network with the greatest total duration, so the project cannot finish sooner than the time it takes to complete that path. Any delay in an activity on the critical path directly extends the project end date because those activities have zero slack. Activities not on this path can have some delay without delaying the overall project, which is what slack (or float) measures. In practice, you determine this by a forward pass to get earliest start/finish times and a backward pass to get latest start/finish times; the activities whose earliest and latest times coincide have zero slack and constitute the critical path. If multiple paths share the same duration, there can be more than one critical path.